Compensatory changes in cortical resource allocation in adults with hearing loss

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Cognitive Neuroscience

Background:

• Hearing loss is linked to cognitive decline and dementia in adults.
• The occurrence of cortical reorganization in early stages of hearing loss and auditory processing is not well understood.

Purpose of the Study:

• To investigate compensatory neural plasticity in adults with mild-to-moderate hearing loss.
• To examine early changes in auditory processing and cortical resource allocation.

Main Methods:

• Utilized high-density electroencephalography (EEG) to record cortical auditory evoked potentials (CAEPs) in response to speech stimuli.
• Analyzed latency, amplitude, and source localization of P1, N1, and P2 CAEP components.
• Compared findings between adults with mild-moderate hearing loss and age-matched normal-hearing controls.

Main Results:

• Adults with hearing loss exhibited increased P2 CAEP latency and amplitude compared to controls.
• Source localization revealed reduced temporal cortex activation and increased frontal cortex activation in hearing-impaired individuals.
• Increased P2 latency positively correlated with poorer performance on speech-in-noise perception tests.

Conclusions:

• Cortical resource allocation changes are evident even in the early stages of adult hearing loss.
• These passively elicited cortical changes are associated with behavioral outcomes in speech perception.
• Findings suggest early compensatory plasticity in the auditory cortex in response to hearing decline.